(People are doing something to organise the mess of background tags and that's great. Sometimes all that annoyin' attention to detail comes in handy☺)
While we're at it, what do we call those backgrounds that reinforce the idea present in the foreground characters, or what they're doing; or somehow echo what's going on in the foreground in some other way...
... without being a simple blow-up of the main character? Is this enough of a thing? Not locations normally, sometimes patterns but not always. Might help express high-falutin' abstract concepts or mental states like avarice or appreciating/making music.
(I'd say abstract background but that seems to be a different thing: mostly a load of plain backgrounds if someone wants to have a go at sorting them out...)